Drug delivery apparatus and method

ABSTRACT

A nebulizer ( 1 ) comprises one or more removable components ( 5,7,9,13 ), for example a mesh assembly ( 9 ), mouthpiece, plunger assembly ( 7 ) and medication chamber ( 13 ), each having an associated data carrier ( 5   a   , 7   a   , 9   a ). The data carrier ( 5   a   , 7   a   , 9   a ) can be used to store information indicating the type of removable component ( 5,7,9,13 ) that is fitted to the nebulizer ( 1 ). A removable component ( 5,7,9,13 ) may be from a set of such removable components. For example, a mouthpiece ( 5 ) fitted to the nebulizer ( 1 ) may be from a set of mouthpieces having different flow rates. The data carrier ( 5   a   , 7   a   , 9   a ) may also be used to control operation of the nebulizer ( 1 ). A data carrier ( 9   a ) attached to a mesh ( 9 ) may be used to prevent the nebulizer ( 1 ) from being used when the mesh ( 9 ) has been used a predetermined number of times.

FIELD OF THE INVENTION

The invention relates to a drug delivery apparatus and method and inparticular to a nebulizer used for drug delivery, and a method ofoperating such a nebulizer.

BACKGROUND OF THE INVENTION

Nebulizers, or atomizers as they are sometimes called, are devices thatgenerate a fine spray or aerosol, usually of liquid. A particularlyuseful application for nebulizers is to provide a fine spray containinga dissolved or a suspended particulate drug for administration to apatient by inhalation.

Piezo-mesh based nebulizers are commonly used to generate aerosols insuch drug delivery apparatus, whereby a piezoelectric element vibrates amesh to produce the fine aerosol spray. In particular, dropletsdispensed on the mesh are vibrated by the piezoelectric element tocreate the spray. There are two principle designs in such piezo-meshbased nebulizers. U.S. Pat. No. 5,938,117 and U.S. Pat. No. 6,983,747disclose one type of design whereby the piezoelectric element is bondedto a mesh element, whereas U.S. Pat. No. 6,651,650 and U.S. Pat. No.6,405,934 disclose designs whereby the mesh element is separate from thepiezoelectric element. An advantage of having the mesh element separatefrom the piezoelectric element is that the mesh element is cheaper tomanufacture and so can be replaced more frequently.

However, a common disadvantage of all mesh based nebulizers is that auser is required to clean the mesh after use, otherwise the mesh holesmay become blocked. There are in the region 5000 2 μm holes in a typicalmesh, and these can easily become blocked by particulates in theenvironment or from salt crystals (i.e. because the drugs are oftensaline based).

The cleaning method is normally to wash the mesh in warm soapy water forabout five minutes, and then rinse and dry the mesh. This process cantake as much time as the drug treatment itself, and is therefore asignificant burden on the patient. Hence, over time, even with goodcleaning the performance of the mesh will deteriorate as more holesbecome blocked—this may typically happen over a number of weeks. Oncethe mesh becomes blocked it is very difficult to clean the mesh andremove a particulate which is lodged in a hole, so it is necessary toreplace the mesh. Although meshes are designed to last for up to twelvemonths, they typically have to be replaced every three months, or evenon a monthly basis for some patients due to poor cleaning.

Such drug delivery apparatus also typically comprise one or moreinterchangeable parts, for example interchangeable mouthpieces,interchangeable plunger assemblies and/or interchangeable medicationchambers. These interchangeable parts enable a nebulizer to be adaptedor customized to best suit the needs of a particular patient. Forexample, different mouthpieces can be selected depending on the volumeof inhalation preferred by a particular user, while different medicationchambers can be selected to provide different volumes depending on thedrug to be delivered.

A disadvantage of having such interchangeable parts is that the drugdelivery apparatus must know which particular part from a set ofinterchangeable parts is fitted at any particular time, so that the drugdelivery apparatus is able to control the delivery of the drugaccordingly.

It is an aim of the present invention to provide a drug delivery systemthat helps alleviate or reduce one or more of the disadvantagesmentioned above.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided anebulizer comprising a removable component comprising a data carrier,and a data reader for communicating with the data carrier of theremovable component.

The removable component may be one of a set of associated removablecomponents. The data reader thereby enables the nebulizer to determinewhich removable component from the set of removable components isattached to the nebulizer, thus enabling the operation of the nebulizerto be controlled accordingly.

According to another aspect of the invention, there is provided a methodof operating a nebulizer, the method comprising the steps of receivinginformation from a data carrier associated with a removable component ofthe nebulizer, and controlling the operation of the nebulizer based onthe information received from the data carrier.

According to another aspect of the invention there is provided a meshassembly for use in a nebulizer, the mesh assembly comprising a datacarrier for communicating, in use, with a data reader provided in thenebulizer.

According to another aspect of the invention there is provided amouthpiece for use with a drug delivery apparatus, the mouthpiececomprising a data carrier for communicating, in use, with a data readerprovided in the nebulizer.

According to another aspect of the invention there is provided amedication chamber for use with a drug delivery apparatus, themedication chamber comprising a data carrier for communicating, in use,with a data reader provided in the nebulizer.

According to another aspect of the invention there is provided ametering chamber for use with a drug delivery apparatus, the meteringchamber comprising a data carrier for communicating, in use, with a datareader provided in the nebulizer. The data carrier provides informationrelating to the metered drug dose to the nebulizer.

According to another aspect of the invention there is provided a plungerassembly for use with a drug delivery apparatus, the plunger assemblycomprising a data carrier for communicating, in use, with a data readerprovided in the nebulizer.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show moreclearly how it may be carried into effect, reference will now be made,by way of example only, to the following drawings in which:

FIG. 1 shows a nebulizer according to an embodiment of the presentinvention;

FIGS. 2 a to 2 c show a mesh assembly of a nebulizer in greater detail,according to another embodiment of the invention;

FIGS. 3 a to 3 c show a mesh assembly of a nebulizer in greater detail,according to another embodiment of the invention;

FIG. 4 shows a flow chart describing the steps performed by oneembodiment of the present invention;

FIG. 5 shows a nebulizer according to another embodiment of the presentinvention;

FIG. 6 shows a flow chart describing the steps performed by anembodiment of the present invention;

FIG. 7 shows a flow chart describing the steps performed by anembodiment of the present invention; and

FIG. 8 shows a nebulizer according to another embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The embodiments below will be described in relation to piezo-mesh typedrug delivery apparatus. It is noted, however, that some embodiments arenot necessarily limited to such piezo-mesh drug delivery apparatus, forexample the embodiments relating to nebulizers having interchangeablecomponents such as mouthpieces and medication chambers. Also, it isnoted that the term nebulizer can be used interchangeably with the termdrug delivery apparatus or atomizer, and is intended to cover otherforms and designs of nebulizer other than the specific type of nebulizerdescribed below and illustrated in the Figures.

FIG. 1 shows a nebulizer 1 according to an embodiment of the presentinvention. The nebulizer 1 comprises a body 3 which receives one or moreremovable components (i.e. interchangeable parts), such as a mouthpiece5, a plunger assembly 7 and a mesh assembly 9. The mesh assembly 9comprises a mesh 9 b, which is vibrated by a piezoelectric element togenerate a fine spray or aerosol. According to one aspect of theinvention the mesh assembly 9 also comprises a data carrier 9 a. Thedata carrier 9 a communicates with a data reader 11 mounted in thenebulizer 1, for example in the body of the nebulizer. In thisparticular embodiment the data carrier 9 a comprises an RFID tag and thedata reader 11 an antenna, each comprising a coil (with FIG. 1 showing across section of each coil loop, the coil planes being perpendicular tothe plane of the image). The operation of an RFID tag and antenna willbe familiar to those skilled in the art. The invention is intended tocover the use of any type of RFID tagging system including, but notlimited to, passive RFID tags (i.e. which are powered from the energyreceived from the associated antenna) or active RFID tags (i.e. whichare self-powered). As discussed later in the application, other forms ofdata carrier and data reader are also envisaged, without departing fromthe scope of the invention.

The data carrier 9 a associated with the mesh 9 b provides informationrelating to the mesh 9 b to the nebulizer 1, as will be described laterin the application.

In the embodiment of FIG. 1 it can be seen that the body of the meshassembly 9 also forms a medication chamber 13. As such, the data carrier9 a can also be used to provide information relating to the medicationchamber 13 to the nebulizer 1. The plunger assembly 7 comprises amedication metering chamber 15. The medication metering chamber 15 isarranged to feed the drug to be nebulized to the nebulation device fornebulization, while the medication chamber 13 is arranged to hold andretain any of the drug in excess of the volume held in the medicationmetering chamber 15. This allows a unit dose (i.e. vial) of a drug to benebulized to be poured into a reservoir, but only the metered volume ofthe medication metering chamber 15 to be nebulized during treatment,with the remainder or excess of the drug being retained in themedication chamber 13. Further details of the medication meteringchamber 15 and its operation can be found in United States patentUS2003/0146300A1.

Although the embodiment of FIG. 1 shows the medication chamber 13 beingformed using the mesh assembly 9, it is noted that the medicationchamber can be formed as a separate physical entity, in which case themedication chamber could have a separate data carrier for providinginformation relating to the medication chamber to the nebulizer (i.e. aseparate data carrier from that associated with the mesh).

FIGS. 2 a to 2 c show in greater detail a mesh assembly 9 that isconfigured differently to the mesh assembly 9 of FIG. 1. FIG. 2 a showsa plan view of the mesh assembly 9. FIG. 2 b shows a side sectional viewthrough section X-X of FIG. 2 a. The mesh assembly 9 of this particularembodiment is configured such that the data carrier 9 a and mesh 9 b liein the same plane, i.e. co-planar. This has the advantage of enablingthe mesh assembly 9 to be attached to a drug pack. FIG. 2 c shows an endview of the mesh assembly 9. It will be appreciated that in thisparticular embodiment the mesh assembly 9 does not form a medicationchamber 13 as shown in FIG. 1, which means that the nebulizer 1 wouldrequire a separate medication chamber (and possibly a separate datacarrier associated with such a medication chamber).

In a further embodiment, not shown in FIGS. 2 a-2 c, the mesh assembly 9may comprise the mesh 9 b, the metering chamber and the data carrier 9a. The data carrier may provide information on the mesh and the metereddose to the nebulizer which information may be used by a clinician forexample for error checking. For example when the total time of atreatment for a patient is longer then would be expected based on a flowrate of the nebulizer and information from the data carrier on the drugdose and metering chamber volume the clinician may conclude that themesh needs to be replaced.

FIGS. 3 a to 3 c show a further alternative configuration of a meshassembly 9. FIG. 3 a shows a side elevation of the mesh assembly 9,which comprises the data carrier 9 a and the mesh 9 b. FIG. 3 b shows anend elevation, while FIG. 3 c shows a sectional view through section X-Xof FIG. 3 b. According to this particular embodiment the data carrier 9a lies in a different plane to that of the mesh 9 b, which may bedesirable is certain applications, for example to enable the datacarrier 9 a to be located more closely to a corresponding data reader 11of the nebulizer. It will be appreciated that various configurations formounting the data carrier 9 a and mesh 9 b are possible, depending onthe particular application and the type of nebulizer being used.

The data carrier 9 a associated with a mesh 9 b of a mesh assembly 9contains information pertaining to the mesh 9 b, which can be read bythe data reader 11 of the nebulizer 1. For example, the data carrier 9 amay be used to identify the type of mesh 9 b being used. The datacarrier 9 a may contain information on the intended use or lifespan ofthe mesh 9 b, for example how many times the mesh 9 b should be usedbefore being replaced. Preferably the whole mesh assembly 9 (includingthe data carrier 9 a and mesh 9 b) is replaced after a predeterminednumber of uses.

Alternatively, if the data carrier 9 a and the mesh 9 b are detachablyconnected to the body of the mesh assembly 9, then the data carrier 9 aand mesh 9 b may be replaced independently of the main body of the meshassembly 9. For example, the user may purchase a data carrier 9 a and amesh 9 b which are replaced as a set, by fitting a new data carrier 9 aand a new mesh 9 b to the existing body of the mesh assembly 9.

The information received by the data reader 11 may be used by thenebulizer for a number of purposes. According to one embodiment theinformation received by the data reader 11 can be used to count thenumber of times a particular mesh 9 b has been used, and then preventthe nebulizer from being operated after the mesh 9 b has been used apredetermined number of times. The mesh 9 b can therefore be preventedfrom being used in the drug delivery apparatus when its intendedlifespan has expired. Alternatively, or in addition, the nebulizer maybe configured to provide some form of indication or warning to the useronce the intended lifespan has expired, i.e. rather than preventing thenebulizer from being used entirely. This type of indication or warningencourages the user to replace the mesh, but without preventing thenebulizer from being used.

FIG. 4 illustrates the steps that may be performed in a nebulizer havinga mesh that has an associated data carrier, as described above in FIGS.1 to 3. The steps shown in FIG. 4 may be performed as part of a drugdelivery operation, for example in response to a user triggering a drugdelivery operation. In step 401 the nebulizer reads the data carrierassociated with the mesh. In step 403 the nebulizer reads a data fieldon the data carrier to ascertain a count value relating to the use ofthe mesh, and determines whether the count value is equal to apredetermined value. For example, if a particular mesh is intended to beused 255 times and is supplied with a count value of 255, which isdecremented after each use, step 403 may involve checking whether thecount value has reached zero. Alternatively, if the mesh is suppliedwith a count value of zero which is incremented after each use, step 403may involve checking whether the count value has reached a predeterminedvalue, i.e. 255 in this particular example.

If it is determined in step 403 that the count value is not equal to apredetermined value, then in step 405 the count value is updated (i.e.incremented or decremented), and the nebulizer operated to deliver adrug, step 407.

If it is determined in step 403 that the count value is equal to apredetermined value, thereby indicating that the mesh has been used apredetermined number of times, the nebulizer indicates in step 409 thatthe mesh requires replacing. This may involve disabling the nebulizersuch that the mesh can no longer be used.

As mentioned above, as an alternative to preventing the nebulizer frombeing operated after the mesh has been used a predetermined number oftimes, the nebulizer may be configured instead (or in addition) toprovide a warning to the user that the mesh should be replaced. Forexample, the nebulizer may be configured to provide a visual and/oraudible warning when the mesh has reached its expected lifespan.

The nebulizer may also be configured to provide such a warning at apredetermined interval prior to the mesh coming to the end of its life,thereby warning the user to purchase a new mesh.

Preferably the updated count value shown in step 405 is stored on thedata carrier 9 a associated with the mesh 9 b. As such, the data reader11 acts as a data writer in addition to a data reader. In other words,the data reader 11 (for example an antenna) is adapted to transmit datato the data carrier 9 a, as well as reading data from the data carrier 9a. In such an embodiment the data carrier will include, for example, anelectrically erasable memory as will be familiar to those skilled in theart, such as an Electrically Erasable Programmable Read Only Memory(EEPROM). Other forms of data carriers that are capable of storing andupdating a count value are also intended to be embraced by the presentinvention.

As an alternative to the above, the updated count value may be stored inthe nebulizer itself. With such an embodiment the data carrier 9 a mayhave a simpler form of memory device, such a Read Only Memory (ROM)which is programmed once during manufacture with a count valuecorresponding to the intended lifespan of the mesh. However, the formermethod has the advantage of retaining the count value with the devicethat is actually being monitored, which provides a more secureapplication.

It is noted that the data carrier 9 a and data reader 11 can be realizedin alternative ways to using an RFID tag and an antenna. For example,other identifying means such as a barcode, DX or serial interface can beused to communicate information between the mesh and the nebulizer.However, using an RFID tag and an antenna has the advantage of notrequiring any interconnecting electrical contacts, which could otherwisebecome degraded in the type of environment found within a nebulizerdevice.

In addition to the data carrier 9 a being used to store informationrelating to the use of the corresponding mesh 9 b, it is noted that thedata carrier 9 a may also be used to store other information, such asinformation relating to the drug being dispensed. In other words, sincethe data carrier 9 a is used to store information about the use of thenebulizer, the data carrier 9 a may also be used to store otherinformation relating to such use, including the number of drug vials tobe dispensed. Thus, if a mesh of the nebulizer is replaced at the sametime as the drug container, the data carrier 9 a of the mesh can be usedto indicate when the drug container needs to be replaced. Also, asindicated above in FIG. 1, if the mesh assembly 9 forms part of themedication chamber, then the data carrier 9 a may also store informationrelating to the medication chamber.

FIG. 5 shows a nebulizer 1 according to another embodiment of thepresent invention. The nebulizer 1 comprises a body 3 for receiving oneor more removable components, such as a mouthpiece 5, a plunger assembly7 and a mesh assembly 9. As with FIG. 1, the mesh assembly 9 forms amedication chamber 13 (although it is noted that these could be separatephysical components, without departing from the scope of the invention).The plunger assembly 7 comprises a medication metering chamber 15.According to this embodiment the mesh assembly 9 comprises a first datacarrier 9 a, the mouthpiece 5 comprises a second data carrier 5 a, andthe plunger assembly 7 comprises a third data carrier 7 a. The firstdata carrier 9 a associated with the mesh assembly 9 also doubles as amedication chamber data carrier for this particular embodiment. Each ofthe data carriers 5 a, 7 a and 9 a communicate with a data reader 11mounted in the body 3 of the nebulizer 1.

One or more of the removable components 5, 7 or 9 may be a removablecomponent associated with a set of such removable components (i.e. aform of interchangeable part selected from a set of such interchangeableparts). For example, the removable mouthpiece 5 can be from a set ofdifferent mouthpieces that may be fitted to the nebulizer. The nebulizercomprises control means for controlling the operation of the nebulizerdepending on the particular removable component that is attached to thenebulizer at a given time.

For example, FIG. 6 illustrates the steps that may be performed in anebulizer depending on the type of mouthpiece fitted to the nebulizer.In step 601 the nebulizer reads the data carrier 5 a of the mouthpiece5. In step 603 the nebulizer determines the type of mouthpiece 5 that isfitted to the nebulizer using the information gathered from the datacarrier 5 a. Then, in step 605, the nebulizer adjusts or controls theoperation of the nebulizer according to which type of mouthpiece 5 isfitted to the nebulizer.

The mouthpiece 5 is part of a set of associated mouthpieces that may beused with the nebulizer, for example depending on the particularpreference of the user, or which is best suited for delivery of aparticular type of drug.

For example, patients could be supplied with two or more mouthpieceswith varying resistances to suit their personal preference, such as afirst mouthpiece giving a high resistance of about 14-18 liters/min, asecond mouthpiece giving a low resistance of about 24-36 liters/min, anda third mouthpiece giving a resistance of about 40-60 liters/min. Thecontrol software in the nebulizer needs to know which mouthpiece isfitted in order to enable the nebulizer to operate correctly, and thedata carrier 5 a mounted on the mouthpiece can be used to store suchinformation during manufacture.

FIG. 7 illustrates the steps that may be performed in a nebulizerdepending on the type of medication chamber 13 fitted to the nebulizer.In step 701 the nebulizer reads the data carrier of the medicationchamber 13 (which would be the data carrier 9 a in FIGS. 1 and 5 due tothe medication chamber 13 being formed from the mesh assembly 9—aseparate data carrier being provided when the medication chamber isformed from a separate physical entity to that of the mesh assembly). Instep 703 the nebulizer determines the type of medication chamber that isfitted to the nebulizer using the information gathered from the datacarrier 9 a. Then, in step 705, the nebulizer adjusts or controls theoperation of the nebulizer according to which type of medication chamberis fitted to the nebulizer.

The medication chamber 13 is part of a set of associated medicationchambers 13 that may be used with the nebulizer, for example dependingon which particular medication chamber is best suited for delivery of aparticular type of drug.

In some applications more than one volume of drug can be delivered fromthe same drug pack by using different medication chambers. In suchapplications the drug dose information on the data carrier 9 aassociated with the mesh 9 b may not be sufficient for the nebulizersoftware to accurately determine the drug dose. This is improved byadding a data carrier to the medication chamber 13 as described above(or to the metering system) for the medication chamber 13 to uniquelyidentify the drug dose which has been placed in the device.

The nebulizer may be configured to perform other features based on theinformation detected by the data reader 11. For example, the nebulizercan be configured to only start a treatment once a predetermined set ofcomponents are detected as being attached to the nebulizer, such as whenthe mesh assembly 9, mouthpiece 5, plunger assembly 7 and medicationchamber 13 have been detected as being present.

Although the embodiment of FIG. 5 shows a single data reader 11 beingprovided for communicating with each of the data carriers 5 a, 7 a and 9a relating to the mouthpiece 5, plunger assembly 7 and mesh assembly 9respectively, it is noted that the nebulizer may comprise one or moredata readers 11 for communicating with one or more data carriers. Aswith the embodiment of FIG. 1, the data carriers 5 a, 7 a and 9 a may beRFID tags and the data reader(s) 11 an antenna, although other forms ofcommunication means are also intended to be embraced by the presentinvention.

The range of the RFID system may be set so that only assembledcomponents and their associated data carriers are detected by the datareader(s) 11. This has the advantage that RFID tagged components locatednearby, but not affixed to the nebulizer, are not detected by the datareader(s) 11.

This may be achieved by designing and positioning the data reader 11 andassociated data carriers 5 a, 7 a, 9 a so that the field of operation islimited to the shortest range required, and positioning the datacarriers close to the data reader.

FIG. 8 shows an alternative embodiment, whereby the configuration of thenebulizer is adapted to enable the data carrier 7 a associated with theplunger assembly 7 to be brought into closer proximity with the datareader 11, thereby enabling the range of the RFID system to be reduced,and hence reducing the possibility of interference from other devices.As with FIG. 5, the nebulizer comprises a mouthpiece 5 having anassociated data carrier 5 a, a plunger assembly 7 having an associateddata carrier 7 a, and a mesh assembly 9 having an associated datacarrier 9 a.

The nebulizer described in the embodiments above may also adopt one ormore other strategies to help reduce or prevent detection of unwanteditems by the radio frequency tagging system. For example, shielding maybe provided on the side of the data reader 11 that is opposite to theside where the data carriers 5 a, 7 a and 9 a are positioned.

In the embodiments described above the RFID data transmission could beinterrupted by an external RF source such as the piezoelectric elementused to vibrate the mesh, or by mobile phones that are within closeproximity. However, the former does not have a degrading effect on theoperation of the RFID system, since the RFID tags are normally readprior to the drug delivery operation itself, i.e. prior to thepiezoelectric circuit being activated, and hence prior to suchinterference being present. Interference from other sources such asmobile phones can be overcome using data correction techniques commonlyfound in wireless technology, as will be familiar to a person skilled inthe art.

The RFID system may consist of an integrated circuit with a copper coil,which can be encapsulated within a thin plastic film. This may typicallycomprise a product that is about 10 mm in diameter and about 1-2 mmtick. It will be appreciated, however, that other dimensions can also beused depending on the particular nebulizer, and without departing fromthe scope of the invention.

The RFID tag may be integrated into a plastic housing eithermechanically, by potting or over molding to produce a hermeticallysealed assembly as shown in FIGS. 2 a to 2 c or 3 a to 3 c. This plastichousing can also incorporate the mesh required for aerosol generationwhich is typically 10 mm diameter and 0.025-0.5 mm thick, this can alsobe mounted mechanically or over molded. This generates an assemblytypically 35×20 mm and 2-3 mm thick or if the components are mounted coaxially 25 mm diameter and 2-3 mm thick. It will be appreciated,however, that other mounting arrangements and configurations may be usedwithout departing from the scope of the invention.

It is noted that data carriers may also be added to other removablecomponents of the nebulizer, such as ID cards or labels.

Table 1 below illustrates some parameters of the reader coil and tagcoils that may be used, for example, in a nebulizer according to anembodiment of the invention.

TABLE 1 Diameter Distance Offset [cm] Windings [cm] [cm] Alpha Readercoil 4.0 2 0.0 0 Mesh coil 1.0 18 1.3 1.4 0 Mouthpiece coil 1.0 18 1.51.5 45 Plunger 1.0 18 5.6 3.0 45 ID card coil 2.0 0.0 0 Label coil 2.00.0 0 Diameter: Diameter of coil Windings: Number of windings Offset:Offset from center of reader coil Alpha: Angle from plane parallel toreader coil plan

The antenna may be a dedicated antenna, which can be tuned to 13.56 MHz,for example. The antenna may comprise four circular windings with adiameter of 40 mm.

It is also noted that the RFID tag associated with the mesh may containa number of fields related to the mesh and/or the drug and/or thedelivery system. For example, a “Vial Count Remaining” field may be usedto determine when the tag can no longer be used as it is decremented byone each time a treatment is delivered.

Although the embodiments described above have been made in relation tointerchangeable mouthpieces, medication chambers or meshes, it will beappreciated that the invention is equally applicable to any otherinterchangeable part of a drug delivery apparatus, and in particularinterchangeable parts from a set of such interchangeable parts.

The term “removable component” is intended to embrace a part orcomponent of the nebulizer, at least part of which contributes to theactual functioning of the nebulizer, rather than a non-functioning partsuch as the actual drug to be dispensed. In other words, at least partof the removable component is a physical part of the actual nebulizer,which contributes to the physical working of the nebulizer.

Furthermore, although the embodiments of FIGS. 1 and 5 show a nebulizerhaving a removable mesh assembly, a removable mouthpiece, a removableplunger assembly and removable medication chamber, it will beappreciated that not all of these components need necessarily beremovable, or be from sets of interchangeable parts. For example, in theembodiment of FIG. 1 the mouthpiece and medication chamber may be fixedcomponents, rather than removable components.

It will be appreciated from the above that RFID tags are ideally suitedto the described embodiments, as they require no electrical contactsthat may be affected by the saline based drugs often used in the drugproducts to be inhaled, which would otherwise affect alternativeembodiments such as DX or serial interfaces that require electricalcontacts. RFID tags are also more suitable than bar codes as the vialcount can be decremented in the tag itself after each treatment which ismore secure than reading a bar code and decrementing the count withinthe delivery system itself. However, as mentioned above, the inventionis not limited to just RFID tags, and that other identification systemscan be used without departing from the scope of the invention.

It is also noted that the invention can be used with piezo-mesh typenebulizers in which the piezoelectric element and the mesh are bondedtogether, or with piezo-mesh type nebulizers in which the piezoelectricelement and mesh are formed separately.

It should be noted that the above-mentioned embodiments illustraterather than limit the invention, and that those skilled in the art willbe able to design many alternative embodiments without departing fromthe scope of the appended claims. The word “comprising” does not excludethe presence of elements or steps other than those listed in a claim,“a” or “an” does not exclude a plurality, and a single processor orother unit may fulfill the functions of several units recited in theclaims. Any reference signs in the claims shall not be construed so asto limit their scope.

1. A nebulizer (1) comprising: a removable component (5, 7, 9, 13)comprising a data carrier (5 a, 7 a, 9 a); and a data reader (11) forcommunicating with the data carrier (5 a, 7 a, 9 a) of the removablecomponent (5, 7, 9, 13).
 2. A nebulizer (1) as claimed in claim 1,wherein the removable component (5, 7, 9, 13) is one of a set ofassociated removable components.
 3. A nebulizer (1) as claimed in claim2, wherein the data reader (11) is adapted to identify a particularremovable component (5, 7, 9, 13) from its associated set of removablecomponents using information contained in the data carrier (5 a, 7 a, 9a) of the removable component (5, 7, 9, 13).
 4. A nebulizer (1) asclaimed in claim 1, further comprising control means for controlling theoperation of the nebulizer (1), wherein the control means is adapted tocontrol the operation of the nebulizer based on information provided bythe data carrier (5 a, 7 a, 9 a).
 5. A nebulizer (1) as claimed in claim1, wherein the nebulizer comprises at least one further removablecomponent (5, 7, 9, 13) comprising a data carrier (5 a, 7 a, 9 a).
 6. Anebulizer (1) as claimed in claim 5, wherein the control means isconfigured such that the operation of the nebulizer is only possibleonce a predetermined number of removable components (5, 7, 9, 13) aredetected as being attached to the nebulizer (1).
 7. A nebulizer (1) asclaimed claim 1, wherein the data carrier (5 a, 7 a, 9 a) and the datareader (11) comprise a radio frequency identification (RFID) taggingsystem.
 8. A nebulizer (1) as claimed in claim 7, wherein the datacarrier (5 a, 7 a, 9 a) comprises an RFID tag and the data reader (11)comprises an antenna.
 9. A nebulizer (1) as claimed in claim 7, whereinthe range of the RFID tagging system is restricted such that the antenna(11) is suited to communicate with RFID tags (5 a, 7 a, 9 a) mounted inremovable components (5, 7, 9, 13) attached to the nebulizer.
 10. Anebulizer (1) as claimed in claim 7, wherein the removable component (5,7, 9, 13) is one or more of a mesh assembly (9), a mouthpiece (5), aplunger assembly (7) or a medication chamber (13).
 11. A mesh assembly(9) for use in a nebulizer, the mesh assembly (9) comprising a datacarrier (9 a) for communicating, in use, with a data reader (11)provided in the nebulizer.
 12. A mesh assembly (9) as claimed in claim11, wherein the data carrier (9 a) is adapted to store information forpreventing a mesh (9 b) from being used in a nebulizer after apredetermined number of uses.
 13. A mesh assembly (9) as claimed inclaim 12, wherein the data carrier (9 a) stores a count value, the countvalue being incremented or decremented after each use of the mesh.
 14. Aremovable component (5, 7, 9, 13) for use in a nebulizer, the removablecomponent (5, 7, 9, 13) comprising a data carrier (5 a 7 a, 9 a) forcommunicating, in use, with a data reader provided in the nebulizer. 15.A removable component (5, 7, 9, 13) as claimed in claim 14, wherein theremovable component (5, 7, 9, 13) forms part of a set of interchangeableremovable components for use with the nebulizer, and wherein the datacarrier (5 a, 7 a, 9 a) provides, in use, information relating to whichremovable component (5, 7, 9, 13) from the set of interchangeableremovable components is being used with the nebulizer.
 16. A removablecomponent as claimed in claim 14, wherein the removable component (5, 7,9, 13) comprises a mouthpiece (5), a plunger assembly (7), a meshassembly (9) or a medication chamber (13).
 17. A method of operating anebulizer (1), the method comprising the steps of: receiving informationfrom a data carrier (5 a, 7 a, 9 a) associated with a removablecomponent (5, 7, 9, 13) of the nebulizer; and controlling the operationof the nebulizer based on the information received from the data carrier(5 a, 7 a, 9 a).
 18. A method as claimed in claim 17, wherein theremovable component (5, 7, 9, 13) is a mesh assembly (9), and furthercomprising the step of preventing the nebulizer from being used when themesh assembly (9) has been used a predetermined number of times.
 19. Amethod as claimed in claim 17, wherein the removable component (5, 7, 9,13) is a mouthpiece (5), a plunger assembly (7) or a medication chamber(13), and further comprising the steps of controlling the operation ofthe nebulizer based on the type of mouthpiece (5) and/or plungerassembly (7) and/or medication chamber (13) fitted to the nebulizer.